Wrapping machine



R. MAYER June 13, 1967 WRAPPING MACHINE Filed Dec. 24, 1965 FIG. 7

FIG. 2

3,324,524 Patented June 13, 1967 D ,8 8 Claims. (Cl. 53-230) Thisinvention is concerned with a wrapping machine in which articles to bewrapped are each fed with a wrapper through a folding tube, so that thewrapper is folded into U-shape around the article, by one of a number ofdrivers associated with an endless conveyor chain which runs aroundreversing wheels.

In wrapping machines it is known to effect the insertion of articlesinto the folding tube by means of a pusher which is movable to and fro.Since the return movement of the pusher to its initial position in thetiming of the machine involves a dead period, the output of suchmachines is somewhat small. It has, therefore, already been proposed tolet the pusher return to its initial position above or below the path offeed of the articles at the end of each pushing operation. Thisprovision has proved to be satisfactory in machines in which the pusherperforms a short stroke but in machines with a longer pushing stroke,for example wrapping machines for large packages or composite packages,involves an unacceptable overall length of the machine. In order toprevent the pusher returning to. a position in the path of feed of thearticles, it has, moreover, already been proposed to mount one or moredrivers on an endless conveyor chain which circulates in an oval-shapedpath, so that at the end of the feed section, i.e. the section of theconveyor over which the drivers feed the articles through the foldingtube, each driver is drawn downwardly or upwardly away from the rearside of the article being conveyed, is

pivoted out of the path of feed and is returned to its original positionalong another path. A return movement of each driver in a directionperpendicularly with respect to the rear side of the article beingconveyed, as with sliders which are movable to and fro rectilinearly,is, however, not achieved with this type of conveyor movement. This isdisadvantageous insofar as the ends of the wrapper projecting beyond therear side of each article to be wrapped may be disarranged by theslider.

In order to obviate these disadvantages, the present invention providesa machine in which articles to be wrapped are each fed with a wrapperthrough a folding tube, so that the wrapper is folded into U-shapearound the article, by one of a number of drivers associated with anendless conveyor chain which runs around reversing wheels each forming areversing section of the conveyor, and the drivers are each pivotallycoupled to the conveyor chain by at least one rod and are guided instationary rails for movement therealong, the arrangement being suchthat, when the pivot on the conveyor chain of the rod of each driverpasses around a reversin section of the conveyor chain, the driverconcerned is reversed.

In accordance with a further feature of the invention, the rails forguiding the drivers during their feeding movement, i.e. whilst they arefeeding articles through the folding tube, their return movement to aposition in readiness for a fresh feeding movement, and their reversal,are of hysteresis loop form. Thus, each driver is moved out of the pathof feed after leaving the rear side of the article being fed thereby,and is brought back to its original position in readiness for a freshfeeding movement along a path other than the path of feed. The rails mayhave switches at the ends of the said hysteresis loop, each switch beingconstituted by a tongue which controls the reversal of the drivers.

In addition to a more careful handling of the wrappers than in machineswith a reciprocating pusher, an output which is at least doubled, isattained by the machine of the present invention whilst operating at thesame speed of conveyance.

A preferred embodiment of a wrapping machine according to the inventionwill now be described with reference to the accompanying diagrammaticdrawings.

In the drawings:

FIGURE 1 is a longitudinal section through the wrapping machine.

FIGURE 2 is a plan view, partly cut away, of the wrapping machine shownin FIGURE 1, and

FIGURE 3 is a side view, on an enlarged scale, on one of the driversshowing it in a further position from FIGURE 1.

The wrapping machine illustrated in the drawings is particularlysuitable for wrapping large articles G or groups of identical smallerarticles or packages in wrappers E. The method of wrapping chosen forthe present example is that known as pocket folding in which a wrapperis first folded in U-shape around the front, upper and lower sides ofeach article, whereupon the two projecting parts of the wrapper at theends of the article are folded in and then the rear side of the articleis enclosed by the wrapper.

In order to fold a wrapper E in U-shape around an article G, the latteris brought in the known way up against the wrapper E, which is fed in ina vertical plane. The article and the wrapper are then pushed through afolding tube 1 which is provided at both its sides with folding members2, 3 and 4 for folding in the wrapper at the ends of the packagePushingof the articles G is performed successively by four drivers 5 which areconnected to a pair of endless conveyor chains 8 which circulatecontinuously around two pairs of reversing wheels 6, 7 in the directionof the arrows shown in FIGURES 1 and 3. One pair of reversing wheels, 6or '7, is driven by any suitable means, e.g. an electric motor. Each ofthe drivers 5 comprises a pushing plate 10, a frame 11 and a carriage 12and the drivers, are guided in two sets of rails 14 of U-shape in crosssection by means of rollers 13 which are mounted on the carriages i2 andrun in the rails. Pivoted to the carriage 12 of each driver 5 are theends of two rods 15 which are pivotally connected at their other ends tothe conveyor chains 3.

The two sets of rails 14 are arranged below the table 16 of the machineon which the articles G are fed, and the path of these rails is ofhysteresis loop form with two tracks, viz. an upper and a lower track,and two switches constituted by two pairs of pivotable tongues 17 and18. The drivers 5 are drawn along the upper track of the rails andpushed along the lower, return track by the conveyor chains 8. The railsare so associated with the conveyor chains 8 that each driver 5 hasimparted to it a reversing movement at the end of the upper track, i.e.at the end of its feed movement, when the leading pivots of theassociated two rods 15 on the conveyor chains 8 pass around .thereversing section of the chains 8 formed by the reversing wheels 7, sothat, after being influenced by the switch 17 arranged beneath the pathof feed of the articles, i.e. beneath the machine table 16, the driveris pushed to a switch 18 at the other end of the hysteresis loop whereit again receives a reversing movement by the switch 18 and is thendrawn along the upper track.

The lengths of the rods 15 and the diameters of the reversing wheels 6and 7 are so correlated that these parts have the same effect as a crankdrive. In addition,

the switches 17 and 18 are of such a form that, after a O initiation ofthe reversing movement of each driver 5, its carriage 12 isautomatically brought on to the next rail track. Thus, the two pivotabletongues of each switch operate in a similar way to a switch in arailroad system. Provided on each of the pivotable tongues of the switch17 is a counter weight 23 which biases the tongue to a normal restposition in the upper track of the U-section rail 14. Thus, when adriver enters the switch 17 from the upper track, the .tongues are swungdownwardly to allow the driver to move to the position shown in FIGURE1.

The tongues then return to their normal positions and, when the driverconcerned is moved out of the switch, cause it to move on to the lowertrack. The pivotable tongues of the switch 18 are controlled in the samemanner but under their own weight.

During the feed of an article G, a part of the frame 11 with the pushingplate 10 pivoted thereto projects up through a longitudinal slot 19formed in the machine table 16. A pivotable plate 20 is mounted in themachine table 16 for the purpose of guiding each pushing plate 10through the machine table 16 at the end of the feed movement of thedriver concerned. This plate 20 is periodically swung downwardly so thata free space is formed for the passage therethrough of a pushing plate10 (as shown in FIGURE 3). In order to maintain this space small, thepushing plate 10 of each driver is pivoted into a horizontal position onthe return movement of the driver. To this end, there is arranged on thefolding tube 1 a pivotable pawl 21 against which the pushing plate 10,which during feed is held in a vertical position by a permanent magnet22 secured on the frame 11, runs so that the plate is released from themagnet 22 and pivoted through 90.

Since, in the present example, the pivot pins 27 which connect the rodsto the conveyor chains 8, intersect the rails 14 at two parts thereofduring movement of the drivers 5 around the rails 14, each set of rails14 is provided with pivotable parts 28 and 29 to allow for passage ofthe pins 27 therethrough.

The parts of the wrapper at the rear side of the package are .thenfolded down by means of folding members 25, 26 (FIGURE 1) at the workingstation to which the articles G come at the end of their feed by thedrivers 5. The further conveyance of the finished packages to the outletof .the machine is still performed by the drivers 5 as the fresharticles G fed to the said working station advance the precedingarticles.

I claim:

1. A wrapping machine comprising a base frame; a folding tube mounted onthe base frame; an endless conveyor chain which runs around reversingwheels carried by the base frame, each reversing wheel forming areversing section of the conveyor chain; means for circulating .theconveyor chain around the reversing wheels; guide rails fixed to thebase frame alongside the conveyor chain and defining a path constitutedby an upper track and a lower track with intersecting portions; a numberof drivers guided on said guide rails for movement therealong, at leastone rod pivotally coupling each driver to the conveyor chain, eachdriver being arranged to move through the folding tube to push anarticle to be wrapped and a wrapper through the tube so that the wrapperis folded into U-shape around the article; and means associated with theguide rails adjacent the reversing sections of the conveyor chain forswitching the drivers from one track to the other and reversing theirdirection of travel as the pivots on the conveyor chain of the said rodspass around the reversing sections.

p 2. A wrapping machine comprising a base frame; a folding tube mountedon the base frame; an endless conveyor chain which runs around reversingwheels carried by the base frame, each reversing wheel forming areversing section of the conveyor chain; means for circulating theconveyor chain around the reversing wheels; guide rails which are fixedto the base frame alongside the conveyor chain and are of hysteresisloop form defining an upper and lower track with intersecting portionsadjacent the said reversing sections; a number of drivers guided on saidguide rails for movement therealong, at least one rod pivotally couplingeach driver to the conveyor chain, each driver being arranged to movethrough the folding tube to push an article to be wrapped and a wrapperthrough the .tube so that the wrapper is folded into U-shape around thearticle; and means associated with the intersecting portions of thehysteresis loop for switching the drivers from one track to the otherand reversing the direction of travel of the drivers as the pivots onthe conveyor chain of the said rods pass around the reversing sections.

3. A wrapping machine comprising a base frame; a folding tube mounted onthe base frame; and endless conveyor chain which runs around reversingwheels carried by the base frame and has a straight section extendingalongside the folding tube, each reversing wheel forming a reversingsection of the conveyor chain; means for circulating the conveyor chainaround the reversing wheels; a number of drivers, at least one rodpivotally coupling each driver to the conveyor chain such that eachdriver is arranged to move, along the said straight section of theconveyor chain, through the folding tube to feed an article to bewrapped and a wrapper through the tube so that the wrapper is foldedinto U-shape around the article; guide rails of hysteresis loop formfixed to the base frame alongside the conveyor chain and defining anupper and lower track with intersecting portions and with the ends ofthe hysteresis loop and adjacent the said reversing sections, theaforesaid drivers being guided on the guide rails for movementtherealong when feeding articles through the folding tube and when beingreturned to a position in readiness for a fresh feeding movement; andswitches, each constituted by a tongue, at the ends of the hysteresisloop for switching the drivers from one track to the other while thedirection of travel of the drivers is reversed as the pivots on theconveyor chain of the said rods pass around the reversing sections ofthe conveyor chain.

4. A wrapping machine as claimed in claim 3, wherein there are a pair ofconveyor chains which run parallel to, and are spaced from, one another,and two sets of guide rails associated respectively with the twoconveyor chains, the drivers being mounted between the spaced, parallelguide rails.

5. A wrapping machien as claimed in claim 4, wherein the guide rails areof U-shape in cross section for guiding the drivers.

6. A wrapping machine comprising a base frame; a horizontal table whichis mounted on the base frame and on which articles to be wrapped are fedinto the machine; a folding tube mounted in a horizontal disposition onthe base frame above the said table; an endless conveyor chain whichruns around two reversing wheels carried by the base frame and has ahorizontal straight section disposed below and adjacent to the aforesaidtable, each reversing wheel forming a reversing section of the conveyorchain; means for circulating the conveyor chain around the reversingwheels; guide rails fixed to the base frame alongside the conveyor chainand a horizontal upper track and a lower track with intersectingportions adjacent the reversing sections; a number of drivers guided onsaid guide rails for movement therealong, at least one rod pivotallycoupling each driver to the conveyor chain, each driver being arrangedto move, along the said straight section of the conveyor chain, throughthe folding tube to push an article to be wrapped and a wrapper throughthe tube so that the wrapper is folded into U-shape around the article;and means associated with the intersecting portions of the guide railsadjacent the reversing sections of the conveyor chain for switching thedrivers from one track to the other while the direction of the driversis rcversed as the pivots on the conveyor chain of the said rods passaround the reversing sections.

7. A wrapping machine comprising a base frame; a folding tube mounted onthe base frame; an endless conveyor chain which runs around reversingwheels carried by the base frame, each reversing wheel forming areversing section of the conveyorv chain; means for circulating theconveyor chain around the reversing wheels, guide rails fixed to thebase frame alongside the conveyor chain; a number of drivers guided onsaid guide rails for movement therealong at least one rod pivotallycoupling each driver to the conveyor chain, each driver being arrangedto move through the folding tube to push an article to be wrapped and awrapper through the tube so that the wrapper is folded into U-shapearound the article, each driver including a pivotable pushing platearranged to engage an article to be wrapped as the driver is movedthrough the folding tube, and a permanent magnet, Which is mounted onthe driver, for freely holding the pushing plate in a predeterminedposition during feed of an article through the folding tube; and meansassociated with the guide rails adjacent the reversing sec tions of theconveyor chain for reversing the drivers as the pivots on the conveyorchain of the said rods pass around the reversing sections.

8. A wrapping machine comprising a base frame; a horizontal table whichis mounted on the base frame and on which articles to be wrapped are fedinto the machine; a folding tube mounted in a horizontal disposition onthe base frame above the said table; an endless conveyor chain whichruns around two reversing wheels carried by the base frame and has ahorizontal straight section disposed below and adjacent to the aforesaidtable, each re- 6 versing Wheel forming a reversing section of theconveyor chain; means for circulating the conveyor chain around thereversing wheels; guide rails which are fixed to the base framealongside the conveyor chain and are of hysteresis loop form with theends of the hysteresis loop adjacent the said reversing sections; anumber of drivers guided on said guide rails for movement therealong, atleast one rod pivotally coupling each driver to the conveyor chain, eachdriver being arranged to move through the folding tube to push anarticle to be wrapped and a wrapper through the tube so that the wrapperis folded into U-shape around the article, each driver including apivotable pushing plate arranged to engage an article to be Wrapped asthe driver is moved through the folding tube, and a permanent magnet,which is mounted on the driver, for freely holding the pushing plate ina predetermined position during feed of an article through the foldingtube; and switches, each constituted by a tongue, at the ends of thehysteresis loop form rails for reversing the drivers as the pivots onthe conveyor chain of the said rods pass around the reversing sectionsof the conveyor chain.

References Cited UNITED STATES PATENTS 2,817,933 12/1957 Bell et al.53233 X 2,980,038 4/1961 Royer 198-24 X 2,999,345 9/1961 Chalmers et a1.53230 TRAVIS S. MCGEHEE, Primary Examiner. R. L. FARRIS, AssistantExaminer.

1. A WRAPPING MACHINE COMPRISING A BASE FRAME; A FOLDING TUBE MOUNTED ONTHE BASE FRAME; AN ENDLESS CONVEYOR CHAIN WHICH RUNS AROUND REVERSINGWHEELS CARRIED BY THE BASE FRAME, EACH REVERSING WHEEL FORMING AREVERSING SECTION OF THE CONVEYOR CHAIN; MEANS FOR CIRCULATING THECONVEYOR CHAIN AROUND THE REVERSING WHEELS; GUIDE RAILS FIXED TO THEBASE FRAME ALONGSIDE THE CONVERYOR CHAIN AND DEFINING A PATH CONSTITUTEDBY AN UPPER TRACK AND A LOWER TRACK WITH INTERSECTING PORTIONS; A NUMBEROF DRIVERS GUIDED ON SAID GUIDE RAILS FOR MOVEMENT THEREALONG, AT LEASTONE ROD PIVOTALLY COUPLING EACH DRIVER TO THE CONVEYOR CHAIN, EACHDRIVER BEING ARRANGED TO MOVE THROUGH THE FOLDING TUBE TO PUSH ANARTICLE TO BE WRAPPED AND A WRAPPER THROUGH THE TUBE SO THAT THE WRAPPERIS FOLDED INTO U-SHAPED AROUNG THE ARTICLE; AND MEANS ASSOCIATED WITHTHE GUIDE RAILS ADJACENT THE REVERSING SECTIONS OF THE CONVEYOR CHAINFOR SWITCHING THE DRIVERS FROM ONE TRACK TO THE OTHER AND REVERSINGTHEIR DIRECTION OF TRAVEL AS THE PIVOTS ON THE CONVEYOR CHAIN OF THESAID RODS PASS AROUND THE REVERSING SECTIONS.